We're so accustomed to symmetry in the face that when nature throws an eye-color curveball, the effect is pretty striking.
Most of us have two eyes. Most of us have two eyes of the same color. But for those with heterochromia iridis, the irises don’t follow convention – and with complete heterochromia the color of the eyes are altogether different.
While the rate of congenital heterochromia iridis in humans is approximately six out of a 1,000, and many of those cases are very subtle, it is much more common in animals. It’s not wildly unusual to see it in dogs – and felines with it even have a moniker: odd-eyed cats.
Along with Turkish Angoras and Siberian Huskies, among other pussies and pups, it also shows up in cattle, water buffalo and even ferrets. Horses display the trait as well, especially pintos (but none are pictured here as a photo of a horse clearly showing both eyes is a rare thing).
In animals we have a relative lack of the pigment melanin to thank for the condition, which generally happens as a result of the dominant white gene or the white spotting gene creates an area without pigment, leading to a blue eye.
Whatever the backstory is, it’s hard not appreciate the odd, somewhat otherworldly, beauty of these odd-eyed guys and gals.